A radio access technology of a wireless cellular mobile network is developing continuously, aiming to meet a user requirement for a higher rate, a wider coverage, and a larger capacity in the future. A current radio access technology is evolving from a “3G” system into Long Term Evolution (LTE), and further evolves into a “LTE-Advanced” system. In a process in which some user equipments (UE) that support a handover from a base station of a GERAN system to a base station of an LTE system perform an inter-system handover, a UE capability needs to be transferred to the base station of the LTE system by using the base station of the GSM/EDGE radio access network (GERAN) system, and the base station of the LTE system determines, according to the UE capability, how to allocate resources to the user equipments.
In the prior art, because a PS domain of the GERAN system can transmit only an information element of a maximum of 255 bytes, and a CS domain can transmit only an information element of a maximum of 251 bytes. However, a size of a UE capability of the LTE may exceed the 255 bytes, and the UE capability cannot be transmitted in the GERAN system. Therefore, in a handover process, UE capability information received by a target base station may be incomplete, and the target base station cannot determine whether the received UE capability information is complete, and after the handover is completed, the target base station obtains the UE capability information from a UE again regardless of whether complete UE capability information is obtained. Therefore, this method may result in a large number of unnecessary signaling overheads, and a heavy burden on the system.